hi, If you like to spend alot of time in transit, then yes. i did it by air. fastest way to get from point a to b and get out and do something. btw, you may want to define "best". IE cheapest, fastest, most scenic... happy trails.

Carroll, The answer may depend on which part of Ireland you're travelling to? If you're going to Dublin first, the easiest and quickest method would be a budget flight. Travel via train and ferry will not be the quickest or most efficient use of your travel time. Cheers!

Yes, the SailRail ticket is explaned here. The old Dublin Mail with brand new fast trains and ferries. http://www.seat61.com/Ireland.htm Or you could fly with the world's biggest jerk. "We seriously studied removing the restrooms from the planes and adding 2 more rows of seats."

This May we are flying direct, one way, from London City Airport to Dublin for $128 US PP on City Jet, an Air France commuter jet. London City is an easy access from London. Use Skyscanner.com, Whichbudget.com, Kayak.com to find lo-cost inter EU flights. Pay atention to luggage and carry-on rules.

And, following up on Steve's post, there are now 6 airports considered "London Airports." Some of them, like Stansted and Luton, are very far from central London, and will take much more time and/or money to reach. Be sure to factor in the total cost and hassle before booking. For instance, a flight from London City may cost more than a flight from London Stansted, but when you factor in the costs of getting to the respective airports, may actually be cheaper (or be enough less hassle that it's worth the extra money, particularly for an early morning departure).